Gupta S K, Dietzek A M, Veith F J, Torres M, Kram H B, Wengerter K R
Division of Vascular Surgery, Montefiore Medical Center/Albert Einstein College of Medicine, New York, New York.
Am J Surg. 1990 Aug;160(2):182-5; discussion 185-6. doi: 10.1016/s0002-9610(05)80303-4.
Detection of failing arterial reconstructions requires intensive surveillance by frequent physical examination and noninvasive laboratory testing. However, many grafts fail during the intervals between these examinations. For this reason, we have developed an implantable miniaturized piezoelectric flow detection device whose function can be monitored externally by radiotransmission across the skin. Sensors were constructed from ultrathin polyvinylidene fluoride (PVF2) with piezoelectric activity and attached with silicone fixative to 6-mm polytetrafluoroethylene grafts. Ten of these grafts were placed in mongrel dogs as iliofemoral bypasses. Real time data were acquired from the sensors at a rate of 200 Hz, using a DATAQ A/D data acquisition board and CODAS data acquisition software, while simultaneous blood flow (using an electromagnetic flowmeter) and intraluminal pressure were processed by using separate channels of the same data acquisition board. The data were stored on computer storage media and analyzed by the ASYST software, which allows simultaneous signal curves to be compared using regression analysis. In the resting state, the mean blood flow was 123 +/- 16 mL and the mean intraluminal pressure was 124/78 mm Hg, and there was perfect correlation between the PVF2 sensor and the flowmeter and between the sensor and the intraluminal pressure (correlation coefficient, r greater than or equal to 0.99 and r greater than or equal to 0.93, respectively). A tourniquet was applied to the iliac artery proximal to the graft to reduce the flow to approximately half of the resting state (mean flow after tourniquet: 66 +/- 6 mL/minute). Signal tracings from the three sources showed a remarkable similarity with a very high correlation coefficient (r greater than or equal to 0.99 between sensor and flowmeter and r greater than or equal to 0.92 between sensor and the pressure signal). These preliminary results show that the sensors made from low-profile and low-mass PVF2 material have the potential of being implanted around grafts for long-term, continuous monitoring of graft function. Further studies involving long-term implantation to assess the effect of tissue ingrowth and loss of compliance are necessary before this device can be used clinically.
检测动脉重建失败需要通过频繁的体格检查和无创实验室检测进行密切监测。然而，许多移植物在这些检查的间隔期间出现失败。因此，我们开发了一种可植入的小型压电式血流检测装置，其功能可通过经皮肤的无线电传输在外部进行监测。传感器由具有压电活性的超薄聚偏二氟乙烯（PVF2）制成，并使用硅酮固定剂附着在6毫米的聚四氟乙烯移植物上。将其中10个移植物作为髂股旁路移植到杂种犬体内。使用DATAQ A/D数据采集板和CODAS数据采集软件，以200 Hz的速率从传感器获取实时数据，同时使用同一数据采集板的单独通道处理同步血流（使用电磁流量计）和腔内压力。数据存储在计算机存储介质上，并通过ASYST软件进行分析，该软件允许使用回归分析比较同步信号曲线。在静息状态下，平均血流量为123±16 mL，平均腔内压力为124/78 mmHg，PVF2传感器与流量计之间以及传感器与腔内压力之间存在完美的相关性（相关系数，r分别大于或等于0.99和大于或等于0.93）。在移植物近端的髂动脉上应用止血带，将血流减少至静息状态的大约一半（止血带后的平均血流：66±6 mL/分钟）。来自三个来源的信号描记显示出非常高的相关性系数，具有显著的相似性（传感器与流量计之间r大于或等于0.99，传感器与压力信号之间r大于或等于0.92）。这些初步结果表明，由低轮廓和低质量PVF2材料制成的传感器有可能植入移植物周围，用于长期、连续监测移植物功能。在该装置可临床使用之前，有必要进行进一步的长期植入研究，以评估组织长入和顺应性丧失的影响。
